Senegal has held a tightly-contested presidential run-off election between its 85-year-old president and a rival who has the backing of a dozen other opposition leaders.

Voters formed long lines in the capital, Dakar, on Sunday for a poll that analysts say could threaten the stability of one of Africa's most peaceful democracies.

President Abdoulaye Wade faces stiff competition from opposition leader, Macky Sall, as the incumbent tries to win a controversial third mandate.

Analysts say the election could threaten the stability of one of Africa's most celebrated and peaceful democracies.

Senegalese presidential candidate and former Prime Minister Macky Sall speaks to journalists during an interview at his home in Dakar, Saturday, March 24, 2012.

A voter in Dakar says they want this election to be peaceful. No matter who the people choose, she will support whoever wins. She says they are hearing rumors that there could be trouble, and she is praying that all will go well.

The days leading up to the vote were calm, however many worry that disputes over results could reignite street protests.

The incumbent, Abdoulaye Wade, is seeking a third term, despite a constitutional two-term limit passed after he first took office in 2000. The Constitutional Court ruled that he could run in late January, sparking riots that killed at least six people ahead of the first round poll on February 25.

Mr. Wade led that round with 35 percent of votes, followed by Macky Sall who won just under 27 percent.

Senegalese have become increasingly disenchanted with Mr. Wade since the former champion of the opposition came to power in 2000 and won re-election in the first round in 2007.

The 85-year-old president, Africa's second-oldest leader, says he needs more time in office to finish his projects, including a new airport outside Dakar.

Addressing supporters, Mr. Wade says "help me help you!" He says "you know very well that I am a man who takes on challenges." He says "I will face every challenge with you."

Mr. Wade's critics say he has focused too much on large infrastructure projects and not enough on the daily difficulties of the Senegalese.

The president denies allegations that he is trying to secure power for his unpopular son and government minister, Karim.

Macky Sall served in Mr. Wade's government as mining minister, prime minister and president of the National Assembly. He ran Mr. Wade's campaign in 2007. Mr. Sall only left the ruling party in late 2008.

He has been quick to distance himself from his former mentor, promising to reform the government and reduce the cost of daily food necessities.

At a campaign rally, Mr. Sall says he himself experienced the arrogance of the people in power and the president's dynastic conception of rule. He says he thought it was that important to stand and fight back, depending only on the people of Senegal. He says the people are sovereign, and he will serve them.

Mr. Sall has the backing of the 12 other opposition candidates from the first round, as well as popular musicians like Youssou N'dour and the anti-government rap group, "Y'en a Marre," or "We've had enough."

Cheikh Ka says he voted for another candidate before, but he says they are all now backing Macky Sall because they are tired. He says the country has had enough of Mr. Wade.

However, the two politicians' shared history is a stumbling block for some voters.

Awa Laye Fall says she will vote for Macky Sall, not because he is better but because he is all they have. She says they want Mr. Wade out, but she does not trust Mr. Sall. She says she does not think he is that different.

Mr. Sall has run an energetic, populist campaign. President Abdoulaye Wade has prioritized one-on-one visits in regional centers aimed at picking off opposition heavyweights at the local level. He has also secured the backing of influential leaders in the country's Muslim Mouride brotherhood.

Both candidates say they are confident of victory. The electoral commission has called on them to abstain from premature declarations of results in the interest of preserving calm.